Spaghetti is the ultimate comfort food -- it's rich, carb-heavy and easy to prepare. You can get a nostalgia-tinged classic on the table in less than half an hour. Eating spaghetti isn't necessarily the best for weight loss, especially if you cook your noodles until they're very tender. White pasta spaghetti is moderately high in calories, and it has other nutritional qualities that aren't so conducive to shedding pounds. For the better results, choose whole-wheat spaghetti.

Calories and Nutrients in Spaghetti

A cup of cooked white spaghetti contains 221 calories -- a significant chunk of your daily intake if you're on a weight loss diet. For example, a cup of spaghetti will take up 15 percent of your calorie "budget" if you eat 1,500 calories per day, and 18 percent of the calorie budget in a 1,200-calorie diet. Most of those calories come from spaghetti's 43 grams of carbohydrates, but you'll also get 8 grams of protein, plus B-complex vitamins and minerals like selenium and iron.

Whole-wheat spaghetti has slightly fewer calories per serving -- 174 calories per cup -- so it's slightly easier to fit into a weight loss diet. If you eat spaghetti twice a week, switching from white spaghetti to whole wheat will save you almost 5,000 calories per year, or enough to lose 1.5 pounds of fat without making any other diet changes.

Glycemic Index and Weight Loss

If you cook your spaghetti until it's very tender, you're taking in a high glycemic-index meal that might interfere with weight loss. The glycemic index, or GI, measures how significantly a food affects your blood sugar levels. The higher the GI, the faster and more sharply your blood sugar will spike after your meal. That's less than ideal for weight loss, since rapid changes in your blood sugar levels can leave you hungry for your next meal -- even if you didn't eat that long ago. People who follow low glycemic-index diets lose weight more easily than people following high-glycemic index diets, reports the Linus Pauling Institute.

Spaghetti that's been boiled for 20 minutes has a glycemic index of 58, compared to a GI of 46 for white spaghetti cooked for a more moderate amount of time.

Whole-wheat spaghetti is an even better option if you're trying to lower the GI of your diet. It has a glycemic index of 42.

Potential Benefits for Weight Loss

Making fiber-rich foods a regular part of your diet is key for weight loss. Fiber tends to make you feel more satisfied after your meal, because it absorbs water and swells to literally fill your stomach, and fiber-rich foods are harder to chew, which means you're less likely to eat mindlessly. A cup of white spaghetti has 2.5 grams of fiber, which is 10 percent of the daily value.

Whole-wheat spaghetti is a better option for boosting fiber intake. It has over 6 grams of fiber per cup and provides 25 percent of the daily value.

Weight Loss-Friendly Serving Tips

There's more to spaghetti than just the pasta, and you'll need to pick a weight loss-friendly sauce if you want to drop pounds. A half-cup serving of creamy cheese sauce, for example, can add 240 calories -- and 10 grams of unhealthy saturated fat -- to your meal. Tomato sauce, on the other hand, has roughly 30 calories per half-cup serving, which makes it a more diet-friendly topping.

Extend your portion size without adding many calories by serving your spaghetti with lots of vegetables. Mix cooked whole-wheat spaghetti with spiralized zucchini -- which has a spaghetti-like texture -- to eat a bigger portion size, or mix sauteed vegetables into your pasta sauce. Keep it classic by topping your spaghetti with chopped green peppers, onions and mushrooms, or get more experimental by adding chopped kale, black olives and artichoke to your sauce.